computer printers; floppy disk drivers; optical disk drivers; mice; telephones; modems; telephone answering machines; fax machines; video fax machines; walkie-talkies; private branch exchanges (PABX's); cordless telephones; cellular telephones; telephone switching equipment for direct inward system access, namely, private branch exchanges (PABX's) that require only one trunk and that provide a verbal menu for automatic processing of calls; video conference equipment comprising video cameras and video cassette recorders; antennas; global positioning systems (GPS) including receivers; passive directional finding navigators comprising receivers that interrogate and analyze a received radio frequency signal to calculate the direction of the signal source, and computer processors; active directional finding navigators comprising a transponder that transmits a radio frequency signal and receives the reflected signals from an object, and computer processors; automatic telephone dialers; pagers; automatic telephone memory dialers; FM signal generators; and radio relay transceivers